It has been done. Successfully. On the other hand, some have had problems.<br>
<br>
The main issues appear to be that the difference in location of the o-ring groove in the mag tube may cause problems. Do not put the o-ring in the groove when assembling the barrel. Leave it ahead of the groove a bit so it will have a better chance of mating with the rear of the gas chamber (incorrectly called a barrel hanger).<br>
<br>
Another problem is that 1100 forends will not work with nearly all 1187 barrels. The forend needs to be for an 1187 or one of the universal 1100/1187 forends. And note that an 1187 forend does not have the detent ball to hold the 1100 mag tube cap on. You need to put an o-ring under the mag tube cap to act as a kind of lock washer. (This does not apply to the late model 1100s that use the 1187 magazine cap retention system.)<br>
<br>
While putting a 12ga 1187 barrel on an 1100 has been done, it's best to use model specific parts.<br>
<br>
For 20 gauge, forget it. You absolutely cannot swap an 1187 and 110 barrel.